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Speedup worst_slack computation

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This commit is contained in:
Eddie Hung 2018-07-30 18:55:22 -07:00
parent 46b7469652
commit 8371c0dd09
1 changed files with 3 additions and 3 deletions
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6
common/place_common.cc
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@ -40,7 +40,7 @@ wirelen_t get_net_metric(const Context *ctx, const NetInfo *net, MetricType type
WireId drv_wire = ctx->getBelPinWire(driver_cell->bel, ctx->portPinFromId(net->driver.port));
if (driver_gb)
return 0;
float worst_slack = 1000;
delay_t worst_slack = std::numeric_limits<delay_t>::max();
int xmin = driver_loc.x, xmax = driver_loc.x, ymin = driver_loc.y, ymax = driver_loc.y;
for (auto load : net->users) {
if (load.cell == nullptr)
@ -51,7 +51,7 @@ wirelen_t get_net_metric(const Context *ctx, const NetInfo *net, MetricType type
if (ctx->timing_driven && type == MetricType::COST) {
WireId user_wire = ctx->getBelPinWire(load_cell->bel, ctx->portPinFromId(load.port));
delay_t raw_wl = ctx->estimateDelay(drv_wire, user_wire);
float slack = ctx->getDelayNS(load.budget) - ctx->getDelayNS(raw_wl);
auto slack = load.budget - raw_wl;
if (slack < 0)
tns += slack;
worst_slack = std::min(slack, worst_slack);
@ -67,7 +67,7 @@ wirelen_t get_net_metric(const Context *ctx, const NetInfo *net, MetricType type
ymax = std::max(ymax, load_loc.y);
}
if (ctx->timing_driven && type == MetricType::COST) {
wirelength = wirelen_t((((ymax - ymin) + (xmax - xmin)) * std::min(5.0, (1.0 + std::exp(-worst_slack / 5)))));
wirelength = wirelen_t((((ymax - ymin) + (xmax - xmin)) * std::min(5.0, (1.0 + std::exp(-ctx->getDelayNS(worst_slack) / 5)))));
} else {
wirelength = wirelen_t((ymax - ymin) + (xmax - xmin));
}